The instant invention relates to the treatment of textiles and more particularly to a method of treating polyester fabrics to enhance the physical properties thereof.
While polyester fabrics have generally been found to be relatively inexpensive and durable fabrics, they have often been found to be unacceptable for many applications, such as for use in better quality garments. In this regard, most of the heretofore available polyester fabrics have generally been found to have a relatively cold hand and a relatively harsh feel and it has generally been found that they lack many of the aesthetic qualities of other fabrics such as rayon and silk. It has also been found that many polyester fabrics are difficult to sew and/or press and it has been found that it can be difficult to produce sharp creases in many polyester fabrics and/or to remove sharp creases therefrom. It has been further found that many polyester fabrics resist moisture absorption and that they have a tendency to cling due to static electricity build-up.
It has now been found that it is possible to process polyester fabrics so that they exhibit properties similar to those normally associated with silk and rayon. Specifically, it has been found that by treating a polyester fabric in a process wherein it is exposed to a treating solution comprising a wetting agent, a prespecified nonionic fluorocarbon long chain polymer, a softener, a gum and a carrier and wherein it is thereafter exposed to prespecified amounts of both heat and tension it is possible to significantly improve physical properties of the polyester fabric. More specifically, the treating solution utilized in the process of the subject invention comprises between 0.5% and 2% by weight of a conventional textile wetting agent, between approximately 4% and 16% by weight of a nonionic fluorocarbon long chain polymer, between approximately 1% and 6% by weight of a nonionic, cationic or anionic nonsilicone based softener, between approximately 1% and 10% by weight of a natural or synthetic gum and between approximately 66% and 931/2% by weight of a carrier. The nonionic fluorocarbon long chain polymer comprises a copolymer of at least 25% by weight of a fluoroalkyl monomer and an alkylvinyl ether having the formula CH.sub.2 .dbd.CH--OR wherein R represents a halogen substituted lower alkyl group. The carrier comprises water and/or a water soluble organic solvent, wherein the solvent is of a type which can be volatilized at a temperature below 360.degree. F. without leaving a significant residue and also of a type which can be mixed with the nonionic fluorocarbon long chain polymer without reacting therewith. In accordance with the method, after a polyester fabric has been exposed to a treating solution of this type it is heated to a temperature sufficient to evaporate substantially all of the carrier therefrom, and it is then heated to a temperature of between 360.degree. F. and 440.degree. F. in order to effect curing of the fabric and the remaining components of the treating solution thereon. In addition, prior to, during and/or after heating the fabric to evaporate the carrier and/or to effect curing of the fabric and the remaining solution ccmponents thereon, it is exposed to both warpwise (longitudinal) and fillingwise (transverse) tension of between approximately 0.5 lbs per linear inch and 2 lbs. per linear inch. In the preferred form of the method the carrier comprises a water alchohol mixture and the polyester fabric is exposed to the treating solution by immersing it therein and thereafter passing it through a mangle. Specifically, the fabric is passed through a mangle to achieve a pick-up corresponding to an add-on of between approximately 1% and 6% of the weight of the fabric of the fluorocarbon long chain polymer, an add-on of between approximately 0.25% and 4% of the weight of the fabric of the softener and an add-on of between approximately 0.25% and 4% of the weight of the fabric of the gum. Further, the curing step is preferably effected by heating the fabric to a temperature of between approximately 360.degree. F. and 440.degree. F. for a period of up to 25 seconds and by immediately thereafter cooling the fabric to a temperature of less than approximately 300.degree. F.
It has been found that fabrics treated in accordance with the method of the instant invention exhibit substantially improved physical properties. Specifically, it has been found that treated fabrics generally exhibit softer, rounder, smoother hand properties which are more similar to those normally associated with silk or rayon. It has also been found that fabrics treated in accordance with the method exhibit softer more homogenous light refraction properties which significantly improve their appearance characteristics. It has teen further found that they have improved water absorption properties and improved resistance to staining. In addition, it has been found that treated fabrics are generally more resistant to heat and resultant shrinkage during drying and ironing and that they are more receptive to ironing so that sharp creases can be readily produced therein or removed therefrom. Even further, it has been found that fabrics treated in accordance with the method have improved resistance to static electricity buildup and that they generally have less internal stresses from processing during manufacturing than untreated polyester fabrics so that they are generally capable of closer pattern identification. Even still further, it has been found that fabrics treated in accordance with the method can be more easily molded to prescribed patterns and that they have improved resistance to fraying.
Accordingly, it is a primary object of the instant invention to provide an effective method of treating polyester fabrics to improve the physical characteristics thereof.
Another object of the instant invention is to provide a method of treating polyester fabrics to make the physical properties thereof similar to those of silk and rayon.
An even further object of the instant invention is to provide an effective treated polyester fabric.
As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceeding them, and all changes that fall within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents, are therefore intended to be embraced by these claims.